水稻品种抗性对虫体酯酶的影响

THE EFFECTS OF ANTIBIOTIC RESISTANCE OF RICE VARIETIES ON THE ESTERASE CONTENTS IN BROWN PLANTHOPPER

采用苗期群体鉴定法对供试水稻品种进行了抗性鉴定,在此基础上测定了取食不同抗性水稻品种的褐稻虱(Nilaparvata lugens)羧酸醑酶、酸性及碱性磷酸酯酶活力的变化。结果表明,取食感虫品种的褐稻虱若虫及第2代若虫体内上述三种酶的活力明显高于取食抗虫品种的;取食中抗品种的褐稻虱若虫三种酶的活力介于取食感虫和抗虫品种的若虫之间。这一结果与褐稻虱在不同抗性水平上水稻品种的存活率和发育进度是一致的。表明抗虫品种对褐稻虱具有抗生机制,从而抑制了虫体的正常生长发育。取食不同水稻品种的褐稻虱的羧酸酯酶米氏常数(Km)值无明显差异,但最大反应速度(Vmax)值差异极显著。取食感虫品种的 Vmax 值明显高于取食抗虫品种的。这表明取食不同抗性水稻品种的褐稻虱羧酸酯酶性质相同,差异主要是由于酶量的不同。

The seedling bulk screening method was adopted for identificatingthe resistance of rice varieties to brown planthopper(BPH)Nilaparvatalugans St(?)l.The activities of carboxylesterase,acid- and alkaline-phosphatase of BPH fed on rice varieties with different levels of BPH re-sistance were tested.The results showed that the activities of thesethree enzymes in second generation BPH nymphs fed on susceptible va-rieties were significantly higher than those fed on resistant varieties,and those fed on medium resistant varieties were mediate.The resultswere consistent with the tendencies of survivals and developmentalrates of BPH fed separately on the three kinds of varieties;indicatedthat the rice varieties possess antibiotic mechanism which inhibited thedevelopment of BPH,There were no significant differences among theKm values of carboxylesterase in BPH fed on different rice varieties;while the V_(max) valucs of BPH fed on sensitive varieties were obvi-ously higher than those on resistant ones.It was suggested that therewere no qualitive but quantitive differences of carboxylesterase in BPHfed separately on rice varieties with different BPH resistance.